# Samoa declares Monday, Tuesday holidays for people to adjust to change
# Supreme Court rejected constitutional challenge to change
# Drivers in Samoa's biggest neighbors, New Zealand and Australia, use the left side
# Sweden, Iceland, Nigeria and Ghana switched from driving on left side to the right (CNN) -- Samoa will switch its driving from the right side to the left side of the road on Monday in a move opponents have called ill-conceived and said will lead to dozens of wrecks and fatalities.

Proponents tout the change, which no other country has attempted since the 1970s, as making economic sense.

Thousands of angry Samoans protested in the streets, and one group -- People Against Switching Sides (PASS) -- unsuccessfully challenged the constitutionality of the change in the country's Supreme Court.